Calories (cal) to British thermal units (BTU) Conversion
Calories
The calorie (cal) is a unit of energy equal to exactly 4.184 joules, defined as the energy required to raise the temperature of one gram of water by one degree Celsius at 15 °C. This is the thermochemical calorie — distinct from the food calorie (written as Cal or kcal), which is 1,000 times larger. The calorie originated in 19th-century thermodynamics before the joule was established as the SI standard, and persists in chemistry, biology, and food science.
British thermal units
The British thermal unit (BTU) is a unit of energy approximately equal to 1,055.06 joules, defined as the energy required to raise the temperature of one pound of water by one degree Fahrenheit. It remains the standard unit for heating and cooling capacity in HVAC systems in the United States: air conditioners and furnaces are rated in BTU/hour. A typical residential air conditioner is rated at 5,000–24,000 BTU/h. One BTU equals approximately 0.000293 kWh.
| Calories (cal) | British thermal units (BTU) |
|---|---|
| 0.1 cal | 0.000397 BTU |
| 1 cal | 0.00397 BTU |
| 2 cal | 0.00793 BTU |
| 3 cal | 0.0119 BTU |
| 5 cal | 0.0198 BTU |
| 10 cal | 0.0397 BTU |
| 20 cal | 0.0793 BTU |
| 30 cal | 0.119 BTU |
| 50 cal | 0.1983 BTU |
| 100 cal | 0.3966 BTU |
| 1000 cal | 3.9657 BTU |
Frequently Asked Questions (FAQ)
How many British thermal units are in 1 calories?
1 calories (cal) is exactly 0.003966 British thermal units (BTU).
How do I convert calories to British thermal units?
Multiply the value in calories by 0.003966 to get the result in British thermal units. Or use the converter above — type any number and see the result instantly.